In architecture, a boss is a decorative knob on a ceiling, wall or sculpture. Bosses can often be found in the ceilings of buildings, particularly at the keystones at the intersections of a rib vault. In Gothic architecture, such roof bosses (or ceiling bosses) are often intricately carved with foliage, heraldic devices or other decorations. Many feature animals, birds, or human figures or faces, sometimes realistic, but often Grotesque: the Green Man is a frequent subject. The Romanesque Norwich Cathedral in Norfolk, England, has the largest number of painted carved stone bosses in the world; an extensive and varied collection of over one thousand individual pieces. Many of these decorated bosses still bear the original gilt and pigments from the time of their creation. File:Norwich cathedral choir vault (geograph 5461248).jpg|[[Norwich Cathedral]]'s choir vault with multiple bosses File:Salisbury Cathedral Detail Bosses.jpg|[[Early English Period|Early English]] roof bosses in [[Salisbury Cathedral]] File:Abbey Dore painted Green Man.jpg|Green Man roof boss from [[Dore Abbey]], England File:Hereford cathedral 012.JPG|Bosses at [[Hereford Cathedral]], England File:Worcester cathedral 013.JPG|Bosses at [[Worcester Cathedral]], England File:Worcester cathedral 030.JPG|Bosses at Worcester Cathedral, England File:Catedral de Barcelona - 002.jpg|Bosses at [[Barcelona Cathedral]], Spain File:F07 0080.JPG|[[Griffin]] boss at [[Cadouin Abbey]] ([[Dordogne]], France) File:F07 0091.JPG|Boss showing the [[Veil of Veronica]] at Cadouin Abbey, France File:Lienzingen-Liebfrauenkirche 7.JPG|[[Madonna (art)|Madonna and Child]] boss in Germany File:Coluna2.JPG|Bosses at [[Jerónimos Monastery]], Portugal File:St Mark's Cross 1.